Lubricant



is encountered.

Patented Apr. 6, 1943 LUBRICANT Clarence M. Loane, Hammond, Ind., and James 111., assignors to Standard W. Gaynor, Chicago,

Oil

Company, Indiana Chicago, 11]., a corporation of No Drawing. Application March 24, 1941, V 2

Serial No. 384,938 4 27 Claims.

This invention relates to lubricants and particularly to improvements in lubricating oil compositions intended for use in internal combustion engines such as automobile and Diesel engines, under severe conditions wherein corrosion, piston ring sticking, cylinder wear, carbon, and varnish formation may be encountered.

Straight petroleum lubricants are effective within certain defined limits of engine operating conditions and when these limits are exceeded, such lubricantsfrequently fail to give the desired performance demanded of them. Since, in modern engines designed to give increased performance these limits are frequently exceeded, the use of straight mineral oils aslubricants produces undesirable conditions within" the engine; thus varnish and carbon formation is excessive, and corrosion of improved hard metal alloy bearings of the present invention taprovide a lubricant for, internal combustion engines which will be eifective in providing adequate lubrication for such engines.

It is a further object of the invention to provide a lubricant which will not be inducive to the formation of varnish and/or carbon. Another object of the invention is to provide a lubricant which will reduce engine wear and be non-corrosive to bearings. Other objects and advantages of the invention will become apparent as the description thereof proceeds.

We have discoveredthat the foregoing objects It is an object can be attained by employing a lubricating oil containing small amounts of a neutralized or partially neutralized reaction product of a phosnorus sulfide and a mono-olefinic hydrocarbon polymer. This neutralized or partially neutralized product, or a metal derivative thereof, may be used in lubricating oils alone or in combination with the non-neutralized phosphorus sultide-olefin hydrocarbon polymer reaction product.

The phosphorus sulfide-mono-olefin polymer reaction. product, described in a copending application Serial No. 384,936 normally shows a titratable acidity ranging from about 10 to about 50 milligrams KOH per gram of product. In ac- :ordance with the present inventionthis acidic product is treated with an alkaline material, aereinafter described, to effect the neutralization )f at least about 1% of the titratable acidity. It viii be understood that when the neutralization s accomplished with a polyvalent basic material, luch a's lime, a product having excess basicity nay be obtained.

The neutralization of the phosphorus sulfideolefin polymer reaction product may be efiected by adding to the reaction product a suitable alkaline compound such as a hydroxide, a carbonate or an oxide of an alkali or alkaline earth metal, and preferably potassium hydroxide. or alkyl or aryl substituted ammonia such as amines may be used. A neutralized product containing a heavy metal constituent such as, for example, tin, titanium, aluminum, chromium, cobalt, iron and the like, may be obtained by treating the neutralized product with a salt of the desired heavy metal.

The term neutralized phosphorus sulfideolefin polymer reaction product as used herein means a phosphorus sulfide-olefin polymer reaction product having at least about 1% of its titratable acidity, reduced by the reaction with a basic reagent. and includes the neutralized phosphorus sulfide-olefin polymer reaction products containing a metal constituent resulting from said neutralization or resulting from the reaction of a heavy metal salt with the phosphorus sulfide-olefin polymerv reaction product treated with a basic reagent. The final product resulting from the neutralization of the phosphorus sulflde-mono-olefin polymer reaction product, is characterized by the presence or retention of the metal constituent of the neutralizing reagent.

The mono-olefin polymer to be treated may be the polymer resulting from the polymerization of low molecular weight mono-olefins preferably the iso-mono-olefins, such as isobutylene and isoamylene and/or the co-polymers obtained by the polymerization of hydrocarbon mixtures containing iso-mono-olefins and mono-olefins of less than six carbon atoms and preferably those of four carbon atoms. The polymer may be obtained by the polymerization of these olefins or mixed olefins in the presence of catalysts such as sulfuric acid, phosphoric acid, or boron fluoride,

aluminum chloride or other similar halide cata- Y preferably monofor example, liquid isobutylene or a hydrocarbon- Ammonia in which the molecular weight mixture containing isobutylene, butane, and butylene, recovered from petroleum gases especially those gases produced in the cracking of petroleum oils in the manufacture of gasoline. This light fraction may contain from about to about 25% isobutylene, the remainder being sulfide such as P283,

product may be obtained by reacting a phosphorus P285, P487, P453, etc., preferably P285, with an olefin polymer of the type hereindescribed at a temperature of from about 200 F. to about 500 F., and preferably from about 300 F. to about 400 F. It is advantageous to maintain a non-oxidizing atmosphere, such as, for example, an atmosphere of nitrogen, above the reaction mixture. From about 1% to about 50%, and preferably from about 5% to about 25% of .the phosphorus sulfide may be used. Usually it is preferable to use an amount of phosphorus tent of the material treated, is added with vigorous agitation. Excessive rise in the temperature due to the heat of reaction may be avoided by emcient cooling. After the polymerization of the isobutylene together with a relatively minor amount of the normal olefins present, the reaction mass is neutralized, washed free of acidic substances arising from the catalyst, the oily layer separated, and the polymer subsequently separated from the unreacted hydrocarbons by distillation. The polymer mixture so obtained, depending upon the temperature of reaction, varies in consistency from a light liquid to a viscous oily material and contains polymers having molecularweights ranging from about 100 to 2000 or more. The polymers so obtained may be treated with a phosphorus sulfide or the polymer may be fractionated under reduced pressure into fractions of increasing molecular weights, for example,- a tetramer fraction having a boiling point range, between 470 F. and 475 F. and, for example, a distillate having a Saybolt viscosity at 100 F. of about 150 seconds to about 200 seconds, or other desired fractions, and the fractions employed to obtain the desired addition agents. The bottoms resulting from the, distillation of the polymer are well suited for the purpose of the present invention. Bottoms having Saybolt Universal viscosities at 210 F. of from about 50 seconds to about 10,000 seconds, and preferably above about 80 seconds, may be employed.

Another source of an olefinic polymer suitable for the herein intended purpose is a fraction of the polymer obtained in the treatment of a gaseous hydrocarbon mixture containing isobutylene and normal butylene in the presence of a phosphoric acid catalyst in the synthesis of iso-octane. The polymer may be obtained by subjecting a gas mixture comprising less than Cc hydrocarbons and containing C4 olefins and parafiins to temperatures of about 270 F. to about 430 F., preferably about 300 F. to about 330 F., and at a pressure of from about 500 pounds per square inch to about 750 pounds per square inch and preferably about 600 pounds per square inch in the presence of a catalyst such as phorphoric acid on kieselguhr, diatomaceous earth or the like. The mixed polymer obtained comprises essentially a dimer, but contains in addition about 5-10% and usually 6-7% of heavy polymer comprising trimer, tetramer and still higher polymers. This heavy polymer fraction may be separated and treated or it may be still further fractionated to give about 10-15% bottoms, which comprises essentially a teramer fraction boiling between about 400 F. and about 520 F.

The phosphorus sulfide-olefin polymer reaction sulfide that will completely react with the poly-/ mer, for example, 10%, so that no purification is necessary. However, excess phosphorus sulfide may be used and separated from the product after the reaction is completed, by filtering or by diluting with a solvent such as hexane, filtering, and distilling off the solvent. The reaction mixture may be further treated by blowing with steam or nitrogen at an elevated temperature to improve the odor thereof.

As aforesaid, the above described phosphorus sulfide-mono-olefin polymer reaction product is then neutralized with a suitable alkali such as a hydroxide, an oxide, or a carbonate of an alkali or of an alkaline earth metal or with ammonia, and preferably with potassium hydroxide. This neutralization may be carried out by contacting the phosphorus sulfide-polymer reaction product, either as such or dissolved in a suitable solvent, such as naphtha, with a solution of the neutralizing agent, for example, potassium hydroxide dissolved in alcohol. The neutralization may also be accomplished by adding the dry neutralizing agent, such as KOH,-NaOH, NazCOa, KHCOa, CaO, or dry ammonia to the phosphorus sulfide-polymer reaction product, preferably at anelevated temperature of from about F. to about 400 F., preferably in a non-oxidizing atmosphere.

The neutralized product, as aforesaid, may be further treated with a salt of a heavy metal to obtain a heavy metal derivative thereof.

The neutralized product or the heavy metalderivative thereof may be used in lubricating oils alone or in combination with the non-neutralized phosphorus sulfide-polymer reaction product. A much improved lubricant is obtained when a small amount, for example, from about 0.001% to about 10.0%, and preferably from about 0.01% to about 3.0% of the neutralized product is added to a lubricating oil alone, or in combination with about 0.001% to 10.0%, and preferably about 0.01% to about 3.0%, of the non-neutralized reaction product.

As a specific embodiment of our invention the following examples. are given by way of illustration and are not intended as a limitation of the invention.

EXAMPLE I A polymer obtained by treating a hydrocarbon mixture containing about 10% to about 25% isobutylene with boron fluoride at a temperature of about 32 F. was distilled to a bottoms having a Saybolt Universal viscosity at 210 F. of about 3000 seconds.

temperature of 370 F. to 390 F. for about five hours, and then blown with nitrogen for about five hours within this temperature range. This reaction product had a sulfur content of about 6% and a phosphorus content of about 3%.

A portion of this reaction product was then diluted with about 5 volumes of hexane and These bottoms were then reacted with about 10% phosphorus pentasulfideat, a

action product of Example I was neutralized in the following manner. To 300 grams of the reaction product, 9 grams of dry KOH were added at a temperature of 200 F. The temperature was then increasedto about 340 F., maintained at about 340 F.-350 F. for five hours, and then heated within this range for eighteen more hours while bubbling nitrogen through the mixture.

' The final product had an acidity of 10.5 mg.

KOH per gram of product.

Samples of an SAE 20 lubricating oil containing (1) of the above Pzss-isobutylene polymer reaction productof Example I and /2% of the above neutralized Pzss-isobutylene polymer reaction product of Example I, (2) 1% of the above neutralized product of Example II and (3) 1% of the above neutralized product of Example I, were subjected to the hereinafter described tests along with known commercial oils to determine the relative effectiveness of our improved lubricant. In the first test the oils were subjected to an accelerated engine test made in a standard six cylinder automobile motor operating for sixty hours at 35 B. H. P. and 3000 R. P. M. and an oil sump temperature of about 285 F; At the end of the test period the engine was dismantled and given a visual engine rating. In this visual rating a rating of 10 means that the engine had the appearance of the engine at the start of the test, and a visual rating of 5 means that the engine had the appearance of an engine after being lubricated with a good conventional motor oil for a sixty hour period. An engine having an appearance between these extremes is given an intermediate value.

In Table I data on the following oils are tabulated:

Oil A is a high grade SAE 20 motor oil from MC crude oil.

Oil B is a high grade heavy duty bus and truck motor oil.

Oil C is a high grade SAE 20 Pennsylvania -rnotor oil.

Oil D is oil A+ of the Pzss-isobutylene polymer reaction product+/a% of theneutralized PzSs-isobutylene polymer-reaction product of Example I.

Oil E is oil A+1% of the neutralized Pass-isobutylene polymer reaction product of Example II.

Oil F is oil A+1% of the neutralized PzSs-ISO- butylene polymer reaction product of Example I.

TABLE I .\('(.RLER.-\THD ENGINE TEST Visual engine rating at end of 60 hours Piston Sludge Ring hm 32g: Overall varnish deposits carbon carbon rating l0 10 ll) 9+ 9. 8

The condition of the engine after the sixty hour test with oil D was substantiallythe same as that at the start of the test, and was far better than the condition of the engine at the completion of the tests using oils A, B, or C.

Our improved oil is also very stable against deterioration in use as demonstrated by the data in Table II in which are tabulated inspections of the oils at the termination of the sixty hour engine tests.

I Saybolt Universal viscosity at 210 F.

The above data show the marked stability of our improved lubricant.

In a second test about 250 cc. of the oil to be tested is heated at about 330 F.-332 F. in a 500 cc. glass beaker in the presence of five square inches of copper and 10 square inches of iron. Four glass rods of about six millimeter diameter are suspended in the oil which is stirred at about 1300 R. P. M. with a glass stirrer having a 40 blade pitch. At stated intervals oil samples are taken and sludge, acidity and viscosity values determined. The glass rods are also inspected for evidence of varnish formation thereon. Varnish values are based on the visual rating in which a glass rod free of any varnish is given a rating of 10, while a badly coated rod is given a rating of 1. Rods having appearances between these extremes are given intermediate values. Using the same oils employed in the engine tests, the following data were obtained in the above described test.

. I i v armsh 6 mg]. equitii'. lo g. oi si-an anl Oil rods 43 hrs. 24 hrs.l| 48 hrs. 24 hrs. 48 hrs. 24 hrs. 48l1rs.

. I I. 607 30 702 3.7 9.0 s 2 :r 600 40 220 5.5 9.7 r. 700 0 I 1:. 4.5 9.9 10 m 109 n 0 1.1 2.7 10 m 65 0 0 1.4 1.4 10 m 112 0 a2 1.9 2.0 10 m 1 Rating smle-l0=no deposit.

may be employed in other petroleum productssuch as insulating oils, white oils, greases, waxes and the like to increase the resistance thereof to oxidation, sludging and to inhibit the tendency thereof to corrode metals.

While we have described preferred embodiments of our invention, other modifications thereof may be made without departing from the scope and spirit of the invention, and we do not wish to limit our invention to the examples set forth herein except insofar as the same is de fined by the following claims.

We claim: I

1; An improved lubricant comprising a lubricating oil and a small amount of a phosphorus and sulfur-containing phosphorus sulfide-olefin polymer reaction product having at least a portion of the titratable acidity thereof reduced by reaction with a basic reagent.

2. An improved lubricant comprising a lubri cating oil and a small amount of a phosphorus and sulfur-containing phosphorus sulfide-monoolefin polymer reaction product having at least a portion of the titratable acidity thereof reduced by reaction with a basic reagent.

3. An improved lubricant comprising a lubricating oil and a small amount of a phosphorus and sulfur-containing phosphorus sulfide-isomono-olefin polymer reaction product having at least a portion of the titratable acidity thereof reduced by reaction with a basic reagent.

4. An improved lubricant comprising a lubrieating oil and a small amount of a phosphorus and sulfur-containing phosphorus sulfide-isomono-olefin polymer reaction product neutralized by reaction with a basic reagent containing a metal constituent.

5. An improved lubricant as described in claim 4 in which the basic reagent contains potassium.

6. An improved lubricant as described in claim 4 in which the basic reagent contains sodium.

7. An improved lubricant as described in claim 4 in which the basic reagent contains calcium.

8. An improved lubricant comprising a lubricating oil and a small amount of the phosphorus and sulfur-containing reaction product of a phosphorus sulfide and a co-polymer obtained by the polymerization of a hydrocarbon mixture containing low molecular weight isoolefins and normal olefins said reaction product having at least a portion of the titratable acidity thereof reduced by reaction with a basic reagent containing a metal constituent.

9. An improved lubricant comprising a lubricating oil and a small amount of the phosphorus and sulfur-containing reaction product of P285 and. an isobutylene polymer having at least a portion of the titratable acidity thereof reduced by reaction with potassium hydroxide.

10. An improved lubricant comprising a lubricating oil and in combination therewith a small amount of the phosphorus and sulfur-containing reaction product of a phosphorus sulfide and an olefinic hydrocarbon polymer and a small amount of said reaction product having at least a portion of the titratable acidity thereof reduced by reaction with a basic reagent.

11. An improved lubricant comprising a lubricating oil and in combination therewith a small amount of the phosphorus and sulfur-containing reaction product of a phosphorus sulfide and a inono-olefinic hydrocarbon polymer and a small amount of said reaction product having at least a portion of the titratable acidity thereof reduced by reaction with abasic reagent.

12. An improved lubricant comprising a lubrieating oil-and in combination vtherewith a small amount of the phosphorus and sulfur-containing reaction product of a phosphorus sulfide and an iso-mono-olefinic hydrocarbon polymer and a small amount of said reaction product havingat least a portion of the titratable acidity thereof reduced by reaction with a basic reagent having a metal constituent.

13. An improved lubricant comprising a lubricating oil and in combination therewith a small amount of the phosphorus and sulfur-containing reaction product of a phosphorus sulfide and an isobutylene polymer having molecular weight greater than about 500 and a small amount of said reaction product having at least a portion of the titratable acidity thereof reduced by reaction with a basic reagent containing a metal constituent.

14. An improved lubricant comprising a. lubricating oil and in combination therewith a small amount of the phosphorus and sulfur-containing reaction productof P235 and an isobutylene polymer and a small amount of said reaction product having at least a portion of the titratable acidity thereof reduced by reaction with potassium hydroxide.

15. The method of inhibiting the formation of sludge, carbon and varnish in an internal combustion engine lubricated with a mineral lubricating oil, comprising adding to .said mineral lubricating oil a small amount of the phosphorus and sulfur-containing reaction product of a phosphorus sulfide and an olefinic hydrocarbon polymer having at least a portion of the titratable acidity thereof reduced by reaction with a basic reagent.

16. The method described in claim 15 in which the olefinic hydrocarbon polymer is an isomonoolefinic hydrocarbon polymer.

17. The method of inhibiting the formation of sludge, carbon and varnish in an internal combustion engine lubricated with a mineral lubricating oil, comprising adding to said mineral lubricating oil a small amount of the phosphorus and sulfur-containing reaction product of P255 and an isobutylene polymer having at least a portion of the titratable acidity thereof reduced by the reaction with a basic compound having a metal constituent.

18. The method of inhibiting the formation of sludge, carbon and varnish in an internal combustion engine lubricated with a mineral lubricating oil comprising adding to said lubricating oil, in combination, a small amount of the phosphorus and sulfur-containing reaction product of a phosphorus sulfide and an iso-mono-olefinic hydrocarbon polymer, and a small amount of said reaction product having at least a portion of the titratable acidity thereof reduced by the reaction with a basic reagent.

19. A new composition of matter comprising a hydrocarbon oil and a phosphorus and sulfurcontaining reaction product of a phosphorus sulfide and an olefin polymer, said reaction product having at least a portion of the titratable acidity thereof neutralized by reaction with a basic reagent. Y

20. A new composition of matter comprising a hydrocarbon oil and a phosphorus and sulfurcontaining reaction product of a phosphorus sulfide and a mono-olefin polymer, said reaction product having at least a portion of the titratable acidity thereof neutralized by reaction with a basic reagent.

21. A new composition of matter comprising a hydrocarbon oil and a metal-containing and phosphorus and sulfur-containing reaction product of a phosphorus sulfide and an iso-monoolefin polymer, said reaction product having at least a portion of the titratable acidity thereof neutralized by' reaction with a basic reagent containing a metal constituent.

- 22. A new composition of matter as described in claim 21 in which the metal is an alkali metal. 23. A new composition of matter as described in claim 21 in which the metal is potassium.

24. A new composition of matter as described 10 in claim 21 in which the metal is sodium. 

